Workload regulator for automated production

ABSTRACT

A workload regulator for controlling the flow of articles between work stations at which the articles are produced. 
     The apparatus receives a continuous flow of articles on various inbound tracks, subdivides the continuous flow into individual arrays or groups of articles, picks up these groups of articles and deposits them in trays for transient storage, removes them from trays and transfers them to one or more outbound tracks, or transfers the groups from inbound to outbound tracks in a buffer area. The apparatus also positions as needed the trays into which plural groups of articles are being placed during the filling, or from which the groups are being taken as the tray is emptied. Also, the apparatus adds or withdraws trays, as needed, from magazines which hold full and empty trays, respectively. 
     The apparatus may have more than one transfer apparatus and may include equal or unequal numbers of inbound and outbound tracks. The handling sequence of articles is determined in response to the actual output production of an upstream machine work station and the infeed requirements of a downstream machine work station.

BACKGROUND OF THE INVENTION

The present invention relates generally to improved apparatus for massproduction manufacturing, and in a presently preferred form, to anapparatus for dynamically regulating input and output workloads toachieve efficient operations.

In one form, an apparatus made according to the invention receivescontinuous input of separate articles such as can ends in long"strings", and subdivides them into individual arrays or "sticks", inwhich form the ends or like articles are handled so as to insure thatthe output of one or more manufacturing machines may be accommodated byone or more additional processing machines located downline ordownstream thereof, while permitting all such machines to operate eithercontinuously or intermittently without loss of production.

The preferred form of apparatus includes means for transiently storingexcess sticks of can ends, for example, in containers such as open toptrays which are filled stick by stick with the can ends; the trays mayalso be previously filled and act as the source of the main supply, oran extra or supplementary supply of ends which are in turn fed tomachines downstream of the apparatus. Thus, the sticks of ends may besent directly downstream or stored transiently, and the outbound endsupply may be supplemented from time to time by sticks of ends takenfrom storage.

Referring to the preferred form of apparatus, this unit consists of whatmay be referred to as a load regulator and includes a magazine forstoring a series of empty trays, a magazine for storing a series of fulltrays, a transfer assembly for picking up sticks of can ends andsequentially loading them into predetermined areas of empty storagetrays to fill the trays, or, in the alternative, to unload full trays ofends, stick by stick. All such operations are done under automatedcontrol to insure that temporary dislocations and transient changes ofmachine output and demand rates will not affect the overall productivityof all industrial operation.

By way of further background, for example, the can manufacturingindustry is one wherein high quality products, and product components,must be routinely manufactured at incredibly high rates whilemaintaining exceptionally high quality. It is not now unknown for theshells from which complete can ends are made, to be manufactured in asingle press at rates of up to 3,500 shells per minute from a single diepress. Machines are now being built wherein the manufacturing rate froma single machine having two sets of dies will produce 5,200 shells perminute, and still further improved machines are in prospect which willproduce up to 7,000 or more shells per minute. Multiple machines, ofcourse, add to the manufacturing speed potential in this and otherindustries.

As is typical with many modern industrial operations, the overallmanufacturing operation is subdivided into a plurality of individualcomponent-making steps, and each of these steps is further subdividedinto a sequence of further individual steps. As the cyclic rates ofmanufacturing machines increases, the importance of flexibility inmanufacturing becomes apparent.

Quite clearly, only brief dislocations with machinery downstream ofmanufacturing machines operating at these speeds could either causeexcess "stack-up" of parts forced to be arrayed and transiently storedbefore difficulties or delays in the downstream machines has beenaccomplished. Often, the upstream machines are simply stopped becausetransient storage has been impractical. By the same token, if a veryhigh speed upstream machine is to be stopped briefly for machine repairor inspection, it is almost always still desirable to maintaincontinuous operation of machines downstream of such inactivated machine.This requires that articles be available from storage, since thearticles are not then being manufactured. Effective workload regulationis likewise desirable under these circumstances.

Referring specifically to one application of the workload regulator ofthe present invention, manufacturing can ends in the beer and beverageindustry is subdivided into a shell press operation wherein feedstock,usually in coil form, is supplied to a press which, with each stroke,produces a plurality of can ends from coiled sheet stock. These ends arein the form of metal disks to which a substantial third dimension orcountersink has been imparted, and to which a so-called curl has alsobeen imparted. These individual can end shells emerge from the shellpresses in a plurality of strings, which strings of ends are then fed toa downstream machine such as a so-called end liner. The liner fills theperipheral channel or curl in the can end with a plastisol or likegasket-forming material which is necessary to form a fluid- andgas-tight seal between the end and the can body when the two are seamedtogether after the can has been filled.

In one form, after end shells are stamped or drawn and curled, and afterthey have been aligned, the can ends thus formed are fed to so-calledconversion presses wherein an easy-opening feature is imparted to thecan end by scoring a tear-out area and affixing a pull tab to it. Theconversion presses are customarily fed a supply of can ends and acontinuous roll of aluminum tab sheet stock material. Easy-opening endsthus formed are then stored on site or transferred to the can fillingsite.

With can making equipment being operated at such phenomenal speeds, itis considered ideal to have the operating speeds of the machines and thenumbers of such machines carefully matched so as to avoid transientover-or under-capacity during manufacturing. However, this idea israrely able to be maintained in practice, for reasons of maintenancerequirements, unforeseen breakdowns, changes in scheduling, or the like.If these events occur, as they often do, it is still desired to maintainthe projected manufacturing rate in spite of discontinuity and/ordislocation.

Even when a relatively minor breakdown occurs, for example, in one areaof the manufacturing operation, this in turn may necessitate undesirablealternatives of ceasing manufacturing, or being required to accommodatetemporary over-capacity by storing a partially manufactured product;this action itself creates its own set of problems, namely, that ofattending to quality control in an interrupted manufacturing operation.

At present, the possibility of manufacturing dislocations with presentlyknown high speed machines is such that can end manufacturing iscustomarily accommodated by non-automated feeding and transfer betweenmachines.

According to the present invention, steps previously performed by handare able to be accomplished in a fully or partially automatedmanufacturing operation, with the potential of dramatic cost savings andincreased production being achieved with an actual increase in productquality.

In view of the failure of the prior art to provide effective methods andapparatus for the regulating or balancing the output of plural massproduction machines with the handling capacity of machines locateddownstream or downline thereof, it is an object of the present inventionto provide an improved workload regulator for industrial operations.

Another object of the invention is to provide a workload balancer orregulator to be used in the can making industry.

Yet another object of the present invention is to provide an apparatusfor handling mass produced high quality products such as can ends, and,in particular, to receive continually manufactured quantities of suchproducts from plural sources, and to transiently array them in groupsand place the groups in temporary storage, while simultaneouslytransferring other of such products directly to a downstream workstation, with inflow and outflow being controlled so as to balance orregulate differing rates of article production or supply, and demand orcapacity.

A further object of the invention is to provide apparatus for handlingmass produced parts such as can ends and which includes a plurality ofstations, including an accumulation station for receiving plural,substantially continuous inputs or "strings" of can ends, an inboundstaging area at which the strings are subdivided into individual arraysor "sticks", an apparatus for transferring such sticks of can ends intoany one of a plurality of tracks in an outbound staging areas, or in thealternative, to a storage position, and wherein the subdivision intosticks, storage of incoming sticks and feeding and/or supplementing ofoutgoing sticks is accomplished as a part of a single, ongoing process.

Another object of the invention is to provide an apparatus which iscapable of storing plural arrays or sticks of articles such as can ends,and continually adding to or taking from the stored quantity of sucharticles, as indicated by the quantity of articles being fed to theapparatus on the one hand and being accommodated by machines downline ofthe apparatus on the other hand.

Yet another object of the invention is to provide an apparatus forhandling can ends or the like which includes means for receiving pluralstrings of can ends from individual shell-forming machines, means forsubdividing a plurality of such strings of ends into individual sticks,means for temporarily storing such sticks while additional strings ofends are being fed to the apparatus, and means for repositioning suchsticks of ends, in the alternative, into an outbound staging area, intoan inventory build-up area, as well as transfer means for individualsticks from a previously established storage or built-up inventory area.

A still further object of the invention is to provide a workloadregulator which includes a number of storage containers, storage areaswithin each of the containers for accommodating a plurality of productsarrayed in individual groups, a magazine for accommodating a pluralityof containers filled with articles, and a magazine for accommodating aplurality of empty containers, and which further includes means forpositioning one container being filled or emptied to a succession ofpositions within a transfer station area, so that the containers mayserve as a variable-capacity transient storage area for the purpose ofbalancing inbound and outbound quantities of such products.

Yet another object of the invention is to provide a workload regulatingapparatus which includes plural work stations adapted to handle,respectively, trays or like containers of products, being filled withsuch products, trays from which said products are being emptied, meansfor subdividing incoming products into individual arrays, and means forremoving such arrays of outgoing products with a control apparatus beingprovided for determining the incoming supply rate and the outgoingdemand rate, and for selectively positioning incoming arrays of articlesso they may be placed directly into an outbound staging area or storedtransiently so as to accomplish the objective of regulating the flowrate of the articles between work stations without slowing down theproduction rate of such stations.

A still further object of the invention is to provide a workloadbalancer which is adapted to remove arrays of individual products fromstorage and advance them to work stations downline of the apparatus froman inventory of such materials, even when the apparatus is not receivingfreshly manufactured products so as to continue to supply productsdownline of the apparatus during a cessation of upline manufacturing.

Yet another object of the invention is to provide an apparatus of thetype just described which further includes means for moving additionalarticles to more permanent storage areas and removal from such morepermanent storage areas, whether or not such storage areas serve as aportion of the regulating or balancing apparatus.

A yet further object of the invention is to provide a system forregulation of the supply and demand for component parts in an industrialprocess which includes at least one storage container with a pluralityof storage areas, including means for adding groups of articles to, andtaking them from, the storage areas, and means for moving the containerin either direction relative to a storage and retrieval area at whichsuch parts are added to and taken from storage, together with a controlsystem which moves the container in both directions so as to provide asupply of groups of articles to be taken from storage when needed and toprovide a container for transiently storing articles when required.

Another object of the invention is to provide a load regulator for anindustrial process wherein a continuous stream of articles may besubdivided into groups for handling, and to which apparatus includes twomagazines each adapted to receive a plurality of storage trays receivedwithin the magazines, and a conveyor for transporting a container fromthe first magazine to the second magazine, and from the second magazineback to the first, with one magazine being adapted to receive fulltrays, the other magazine adapted to receive empty trays, and theconveyor being adapted to move a container which is being filled orbeing emptied between a plurality of positions to facilitate groupwiseadditions to or retrievals from the carrier, in combination with acontrol which moves the container toward the full container magazinewhen article groups are being added to the container, and for moving thecontainer toward the empty container magazine while article groups arebeing taken from the container.

Another object of the invention is to provide a method for balancing thework flow of a supply of articles created by machines and being fed in acontinuous array toward a production line destination which includesremoving inbound articles in groups from an inbound lane area andtransferring them to an outbound lane area, determining when the numberof articles called for by the production line destination is less thanthe number of articles being received from the source, periodicallyremoving groups of articles from the inbound area and placing them intrays for transient storage, and when the number of articles called forby the destination exceeds the number being received from the productionsource, supplementing the supply of articles being fed from the inboundlane areas to the outbound lane areas by removing additional articlesfrom storage and adding them to the articles being transferred directlyfrom the inbound lane to the outbound lane.

Still another object of the invention is to provide a method asdescribed above which further includes periodically placing trays filledwith the articles in a filled tray storage area, and periodicallyremoving the empty trays to an empty tray storage area, so as to provideat least one individual tray receiving or providing groups of articles,and full and empty trays to provide respectively additional storedarticles and storage capacity.

A further object of the invention is to provide a method of balancingthe rate at which articles being supplied from a first, upstream workstation with the demand for such articles at a second, downstream workstation, which method includes providing at least one inbound stagingarea for receiving the articles from the first work station, and anoutbound staging area for advancing articles to the second downstreamwork station, and continually removing the articles in groups from saidinbound staging area and transferring them to the outbound staging area,and when the number of articles called for by the second work station isless than the number of articles being received at the inbound stagingarea, periodically removing groups of articles from the inbound stagingarea and placing them in selected areas of storage containers fortransient storage, and when the number of articles called for by thesecond work station exceeds the number of articles being received fromthe first work station, removing the articles in groups from the storageareas of the containers and adding such groups of articles from time totime to the groups of articles already being transferred directly fromthe inbound staging area to the outbound staging area.

The foregoing and other objects and advantages of the invention areachieved in practice by providing an apparatus which includes means forreceiving a continual supply of manufactured articles, transientlyarraying the articles in groups and transferring them from an inboundstaging area in which they are arrayed to an outbound staging area formovement downstream of the apparatus, which apparatus may alsotransiently place some or all of the inbound groups of articles intemporary storage, instead of transferring them to the outbound stagingarea, and which may receive groups of articles from the storage area tosupply them to the outbound staging area as a supplement to the groupsof articles being directly supplied to the outbound staging area.

The apparatus also includes mechanisms for arraying, loading, andstoring both empty and full containers for groups of products, includingmeans providing bi-directional movement of the storage containers topermit the rate at which articles are placed in or removed from storageto be changed from time to time.

The objects and advantages of the invention are also achieved byproviding a method of regulating the rate at which articles beingsupplied from a first work station are advanced to a second workstation, which includes receiving inbound articles in a staging area andadvancing at least some of them to an outbound staging area, as well astransferring groups of inbound articles to transient storage areasinstead of to the outbound area and, in the alternative, supplementingthe supply of outbound articles by adding groups of articles taken fromthe storage area to the outbound groups.

The manner in which the foregoing objects and advantages are achieved inpractice will more clearly be apparent when reference is made to thefollowing detailed description of the preferred embodiments of theinvention wherein like reference numbers indicate correspondence of thedrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plan view, schematic in nature, showing the use of theso-called workload regulator of the invention in use in a canmanufacturing operation wherein the articles being produced areso-called easy opening can ends;

FIG. 2 is a perspective view, with portions broken away, showing certainmajor elements of the workload regulator apparatus of the invention;

FIG. 3 is a view similar to that of FIG. 2, and additionally showing theprovision of certain sensor elements used in the control system of theapparatus;

FIG. 4 is a side view, partly in elevation and partly in section,showing the article accumulator, the article staging areas, a conveyor,and article transfer assembly forming parts of the present invention;

FIG. 5 is a fragmentary elevational view of the article transferassembly of FIG. 4;

FIG. 6 is a front elevational view of the apparatus of FIGS. 2-4;

FIG. 7 is a fragmentary vertical sectional view, taken on an enlargedscale, and showing portions of the container and the article transportassembly used to deposit and retrieve groups of articles therein;

FIG. 8 is a top plan view of the workload regulator apparatus of FIGS.2-4;

FIG. 9 is an enlarged vertical sectional view, with portions brokenaway, and showing portions of the container support elements and thesupport element drive system;

FIG. 10 is a vertical sectional view of the drive mechanism of FIG. 9,taken along lines 10--10 of FIG. 9;

FIG. 11 is an enlarged view, partly in elevation and partly in section,showing certain elements of the container support system and theconveyor for the containers, and;

FIG. 12 is a block diagram showing operation of the workload regulatorsystem.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

While it will be understood that the apparatus of the invention iscapable of use in a number of environments and has application in manyindustries, and while it will be further understood that the apparatusof the invention may have its elements arranged in a variety of ways, adescription of the invention will be given with respect to a form ofapparatus used to receive and transiently store can ends and elementsthereof during the process of manufacture. For this purpose, ageneralized discussion of one application of one form of the apparatuswill be given, following which one basic form of apparatus embodying theinvention will be described in detail.

Referring now to FIG. 1, a schematic view of a manufacturing operationis shown wherein first and second workload regulators, 10,10A are shownin place within a manufacturing operation. As reflected in FIG. 1, acoil of suitably gauged metal stock is shown schematically to beadvanced from a coil feed station generally designated 12 to a so-calledshell press area generally designated 14, and shown to include first andsecond shell press stations 16,18. Each station 16,18 is operativelyassociated with so-called string formers 20,22, whose purpose is toarray the output of the shells formed in the press 14 into a continuous"string" within a conveyor along whose length the shells are fed.

As used herein, a "string" refers to a continuous array of shells orlike parts which are not yet subdivided or grouped, and a "stick" refersto a subdivided group of parts. Each of these conveyors, schematicallyrepresented by lines 24a, 24b, 24c, and 24d, is referred to as an"infeed conveyor".

These infeed conveyors 24a, 24b, etc., have their upstream ends situatedat the output of the string former portions 20,22 of the shell pressstations 16,18 and their downstream ends adjacent to and communicatingwith individual infeed lanes 26a and 26b, etc., in an inboundaccumulator assembly generally designated 28 and shown to form one partof the workload regulator 10.

Opposite the accumulator assembly 28 is a consolidator assemblygenerally designated 29 and shown to comprise a plurality of individualoutbound lanes 30a, 30b, etc. The downstream ends of the outbound lanes20a, 30b, etc, meet at the upstream ends of the outbound articleconveyors shown schematically as 32a, 32b, 32c which in turn have theirdownstream ends feeding so-called end liners generally designated 34a,34b, 34c, respectively. Substantially continuous arrays or strings ofarticles are then in turn feed from the end liners 34a, 34b, 34c totheir respectively associated conveyors 36a, 36b, 36c, whose upstreamends receive lined ends and transmit them to the inbound lanes 26x, 26y,26z of the accumulator 28A portion of the workload regulator 10A. Thisregulator 10A also includes a consolidator area 29A at which individualcan ends or like articles are fed along a plurality of channels 30x,30y, 30z before being fed along conveyors 38a, 38b to tabbing presses40a and along their conveyors 38c, 38d to another tabbing press 40b.

Referring again to the regulator 10, both this apparatus and itscounterpart 10A also include inbound staging areas schematicallygenerally designated 42, outbound staging areas generally designated 44,and a central article transfer station 46 at which is positioned atransfer apparatus (generally designated 48 in FIGS. 2 and 3.) FIG. 1also shows that the regulator 10 includes magazines 50, 52 for empty andfull containers respectively of shells or like products being made fromtime to time.

From the foregoing explanation it will be seen that one general objectof the invention is to provide apparatus and methods for insuring thatthe various work stations may be operated at their full instantaneousproduction capacities without creating supply or demand problems at theindividual work stations. This is done, in simplest terms, bydetermining the respective rates of supply and demand for the articles,and transiently placing in storage, or taking from storage, groups ofarticles sufficient to supplement or diminish the rate at which articlespassing through the load regulators would be supplied directly from theinbound to the outbound lanes or staging areas. If supply and demand areevenly balanced, articles are transferred in groups from the stagingareas fed by the inbound lanes to staging areas adjacent the outboundlanes, without change of the inbound and outbound rate relative to eachother. If not, articles are placed in or taken from storage to achievematching of rates and regulation of workload.

A transfer from inbound to outbound may be thought of, or described as,"direct" even though it may be achieved with one or more intermediate or"idler" steps; by "direct" is therefore meant where the inbound andoutbound rates are the same; this normally, but not always means withoutintervening withdrawal of articles from the inbound areas or addition ofarticles to the outbound areas.

Referring now to FIGS. 2 and 3, several other principal components ofthe invention are shown, and these include the transfer apparatus 48which is movably positionable relative to the framing 49 forming a partof the transfer station 46. The apparatus 10 also includes a magazine 50for empty trays and a magazine assembly 52 for full trays. Theaccumulator 28 and the consolidator assemblies 29 are shown tocommunicate respectively with an inbound staging area 42 and an outboundstaging area 44, these areas are shown in greater detail in FIG. 8.

A deposit and retrieval area 51 is shown to lie beneath the lowermostoperating position of the head position 54 of the transfer apparatus 48.FIG. 2 also shows that means in the form of an accelerator/separatorgenerally designated 56 are provided for subdividing a continuous arrayof can ends or other articles in each inbound lane 26a, for example,into individual groups.

Referring to FIGS. 2 and 3, a hydraulic piston and cylinder type liftunit generally designated 60 is shown to be provided and to form a partof the empty tray magazine 50; a counterpart lift 62 is provided for thefull tray magazine 52.

FIG. 3 shows that a consolidator area generally designated 64 isprovided for each of the plurality of outbound lanes 30a, 30b, etc. forexample; this assembly 64 works in the opposite sense as the subdividingassembly 56 insofar as the latter subdivides continuous "strings" ofarticles into article groups and the consolidator 64 assembles groupsback into continuous strings, or permits groups to accumulate intocontinuous strings, for feeding into the associated conveyor for travelto the downstream work station.

FIGS. 4-7 show additional details of the transfer apparatus 48 which, inone mode, picks up articles from the inbound staging area 42 anddeposits them either in a storage container or in the outbound stagingarea 44, and in another mode picks up articles from a container in thedeposit and retrieval area and deposits them in the outbound stagingarea 44 for passage to the outbound lanes 30a, etc.

More specifically, FIGS. 4-7 show the transfer apparatus 48, the inboundstaging area 42, the outbound staging area 44, and the deposit andretrieval area 51. In addition, details are shown of the storagecontainer in the form of individual trays 64, each having storage areas66 for the can 68. FIGS. 4 and 6 also show means in the form of a crossfeed conveyor generally designated 70 for positioning individual storagetrays 64 during loading and unloading. Additional details are also shownof the accelerator/separator 56 and the cross feed tray conveyorgenerally designated 72.

Referring now to FIGS. 4 and 5, the transfer station 46 is shown toinclude the vertical and horizontal framing members 49 referred toearlier, these being arranged in the generally rectangular form so as toprovide an open area for movement of the transfer apparatus 48. Theapparatus 48 includes a head portion 54 which may include magneticelements 80 if the ends or other parts to be handled are of aferromagnetic material. The head 54 is shown to be supported by opposedmounting brackets 82 depending from support rods 84 housed in tubularguides 86. The piston and cylinder arrangement 88 acts to reciprocate acenter support rod 90 having a clevis 92 at its end, at which it isjoined to a center support bracket 94. Accordingly, vertical movement ofthe rod 90 is accomplished under the control of the piston and cylinderassembly 88 whose operation in turn is dictated by controls (not shown)serving to raise or lower the head 54.

As is best shown in FIG. 4, plungers 96 are provided for insertingdownward pressure on the array of products held in the elements 80 toremove them mechanically. If the articles are held magnetically, theymay be released by a switch (not shown) of a known type.

Movement of the transfer apparatus from side to side is also achievedunder the control of a servomotor, here generally designated 98 andshown to be equipped with a drive belt 100 operating a threaded rod 102which propels the carriage assembly generally designated 53 from side toside, that is, to a position wherein the head 54 overlies either aselected track in the inbound staging area, a track in the outboundstaging area, or a channel in a tray in the deposit and retrieval areas51. In this connection, FIGS. 5 and 8 show the carriage 53 to besupported for horizontal movement by guide ears 104 which embracetransverse support rods 106 extending between frame elements 49 definingthe transfer station. Feedback or horizontal control is accomplishedthrough a another servomechanism part, the position indicator, whichincludes an auxiliary belt 110, and a sensing or comparator mechanism112 of a known kind. The connection between the drive or positioningservomotor 98 and the control or position indicator is such that, as iswell known in the art, the rod 102, which is preferably of an acme orbuttress thread construction, will thus rotate to the degree indicatedby the control mechanism and will then slow down and stop precisely atthe desired point so as to index the head 54 in the desired position ofuse. Thus, the transfer mechanism contains vertical and horizontal driveunits and appropriate controls permitting it to move about as indicatedand to pick up and withdraw arrays of articles received in the stagingareas 42,44 or in the deposit area 51.

Referring again to FIG. 4, the accelerator/separator generallydesignated 56 is shown to include its own framing assembly generallydesignated 120 and shown to include at least one vertically andhorizontally reciprocating blade 122 and blade carrier 124. Thisarrangement is positioned on slide rails 126 permitting it toreciprocate. In use, the blade 122 is lowered as a string of can ends isfed to an inbound lane 26a in the accumulator area 28. When the lane 26ais nearly filled, as determined by a sensor 128 (FIG. 3), the blade 122descends into the string of can ends or like articles to separate them.Immediately thereafter, it rapidly moves forward, advancing the stick ofends generally designated 132 in FIG. 4 so as to separate the trailingedge of this stick or group from the leading edge of the followinggroup. The conveyor generally indicated at 134 continues to exert anadvancing bias pressure on the group of ends, and insures that thisstick, having been separated, is transferred to the inbound staging area42 and will arrive there within the desired time. As shown in FIG. 3,when its leading edge approaches the sensor 136, a signal will begenerated which indicates that this stick is available for handling bythe transfer head 48. The conveyor system 72 for advancing the sticks ofends is of conventional construction in the can industry and is of atype which provides a positive, forwardgoing bias on the stick of canends but which will not damage or destroy them if they meet withresistance to further movement.

Although not shown in detail, it will be understood that a plurality ofincoming arrays of ends, (those in lane 26a, 26b, 26c) may thus besubdivided into individual groups and handled as will appear; three tosix incoming lanes are presently preferred for use in the load regulatorof the invention, although more may be provided.

Referring now to FIG. 6, several other principal elements of theinvention are shown, and the capability of the transfer apparatus 48 tomove the pick-up or transfer head 54 to the deposit and retrieval level51 is shown. FIG. 6 also shows a cross feed conveyor for trays generallydesignated 70, and serving to move empty and full trays or empty andfull trays or storage containers to and from the magazines 50,52.

Referring again to FIG. 6, and in particular to the storage magazines50,52 for full and empty trays, the empty tray magazine 50 is shown toinclude a magazine frame having vertical frame members 140, horizontalmembers 142, and tray guides 143.

Frame members 140 includes one or more journals 144 for accommodating acontinuous chain 146 having pusher bars 148 thereon and forming a partof the cross feed tray conveyor 70 described in greater detail elsewhereherein.

In FIG. 6, an empty tray 64 is shown resting on the conveyor 70 justreferred to. FIG. 6 also shows an operating rod 150 forming a connectorbetween a first drive sector 152 and a second drive sector 154, whichelements combine to comprise a bell crank operable by a piston andcylinder assembly 156, which in turn drives the container or traysupport mechanism to be described in detail.

From FIG. 6, it can be seen that the tray support piston and cylinderassembly is fixed to one of the vertical frame members 140, and that aclevis 158 affixed to a part of the sector 152 provides the sectorconnection. When the clevis 158 is raised, the sector 152 rotates aboutthe axis of the drive shaft 160. This causes the operating rod 150 todraw the right hand or driven sector 154 in a clockwise direction androtate the lefthand drive shaft 162. Each shaft 160,162 is associatedwith a pinion gear 163 (see also FIGS. 9 and 10), the function of whichis described in greater detail herein.

Each magazine 50,52 has an associated tray lift 60,60a. The lift unit 60includes a piston and cylinder arrangement 164 operating a tray supportframe 166 which engages a tray 64 when raised into a position of contacttherewith. The piston and cylinder assembly 164 permits the supportframe 166 to be raised at least to and slightly above the level of thedrive shaft 162 of the tray support mechanisms.

FIG. 6 also shows that magazine 52 has a similar lift 60a having apiston and cylinder assembly 164a and a support frame 166a forming apart thereof. FIG. 6 shows that the full tray magazine assembly 52 isthe same as that of its counterpart 50, except that the tray 64 has aplurality of ends or other articles disposed therein. FIG. 6 also showsthat magazine 52 has a journaling bearing 144a for the left end of thecross feed tray conveyor. Reciprocable container supports 168 operatedby racks 170 and in turn driven by the pinion gears 160, provide forreciprocating movement of the support elements 168 into and out ofsupporting relation with the lower surfaces of the tray 64, as will bedescribed in detail later.

Referring again to the cross feed tray conveyor, a pair of idler rollers172, 174 are shown to be provided, as is a drive sprocket 176 operatedby an electric motor and gear drive 178. This chain type conveyor isconventional in all respects, and is driven intermittently between aplurality of positions under the control of an indexing mechanism orotherwise as is known in the art. Each increment of cross feed conveyormovement serves to position the tray 64 so that its channels 65a, 65bregister with the movement axis of the vertically reciprocable head 54on the transfer mechanism 48.

In use of the apparatus 10, one tray 64 may be in the process of beingremoved from a stack of counterpart empty trays and placed on the crossfeed conveyor as shown, while another, full tray is being added to thestack of full trays in the magazine 52.

Referring to depositing an empty tray 64 on the conveyor 70, the lift 60bearing the tray deposits it by being moved to a withdrawn position. Thetray situated in the transfer area 61, it may be assumed, is travelingto the left as shown in FIG. 6 and is nearly full. The previouslysupplied full tray 64 shown resting on the conveyors 70 in the full traymagazine area 52 is about to be raised by the lift 62 and can be addedto the stack of trays from the bottom in the full tray magazine 52.

For this purpose, the tray 64 is lifted until the upper surfaces of itscorner pieces 182 engage the lower surfaces on the corner pieces 184 ofthe tray 64 disposed above it. In this position, the lift 62 is preparedto support the weight of the entire stack of storage containers. Then,the tray support drive mechanism is actuated, the supports 168 arewithdrawn horizontally and the entire stack is raised in incrementsequal to the height of the tray. The drive mechanism is then operated inthe reverse or extending mode, and the supports 168 engage the bottom ofthe lowermost tray 64. Thereupon the lift 62 withdraws to a retractedposition and the entire stack is supported until repetition of thiscycle, or the reverse cycle. The trays are thus "upstacked" or"downstacked" as indicated.

FIG. 6 somewhat schematically shows, at 186, the provision of variousdrive elements for the conveyors forming parts of the staging and/oraccumulator areas. Since the construction and operation of theseconveyors does not form a part of the apparatus which is novel per se,and since their operation is known to those skilled in the art,additional description thereof is believed unnecessary.

Referring again to FIG. 7, the vertically reciprocating action of thehead and the manner of depositing the sticks or groups of articles suchas the groups of can ends 68, in the channels 65a,65b, etc., is shown.

The reciprocation of the tray from left to right (or vice versa) isindicated by the horizontal arrow.

Referring now to FIG. 9, additional details of the container or traysupport mechanism are shown. Basically, this mechanism consists of aplurality of the container supports 168 referred to above and shows eachof these supports 168 to be journalled within a support channelgenerally designated 190 and shown to include vertical and horizontalguide track elements 192,194. The supports 168 ride over an uppersurface 196 of a frame element 197 and each include a support bar 198,and the rack 170, affixed to or forming a part thereof. The rack 170 isreciprocated by rotation of the drive shafts 160,162, each of whichoperates under control of its associated sector 152, 154 (FIG. 6) whichare in turn actuated as described above. The drive mechanism for thetray supports is preferably housed within a grillwork shroud 202 asshown in FIG. 8.

Referring now to FIG. 11, certain details of the cross feed or trayconveyor 70 are shown. Here, a plurality of shafts 204,206 are shown tocarry drive sprockets 208,210 over which are trained conveyor chains146. The framing members 49,140 support brackets 216,218 on which aplurality of tray rests 220,222 are secured. These tray rests 220,222engage the undersides 185 of the rays 64 and may be made from a block ofsolid, lubricous plastic material such as a polyethelene or TFE(tetrafluoroethylene) material permitting the tray to slide therealongwith minimum friction. The trays are actually advanced by being engagedby the pushers 148, which are in turn affixed to and spaced apart ontheconveyor drive claims 146.

The intermittent bi-directional operation of the conveyor drive chain isalso accomplished with the aid of proximity sensors or other suitablecontrols to provide precise indexing and alignment for the motormechanism 176,178.

Referring again to FIGS. 6 and 8, it will be appreciated that theinbound and outbound staging areas 42,44 are in reality extensions ofthe tracks 26a, 26b, 30a, 30b, formed by the infeed and outfeedconveyors 24a, 24b, 32a, 32b, etc. Drive systems for these units areknown to those skilled in the art, so these elements are shown inrepresentative form only as comprising a mechanism generally designated224 in FIG. 8. In this connection, FIG. 8 also shows that theseparator/accelerator 56 in FIG. 8 lacks a counterpart to act as aconsolidator for the support groups of articles in the outbound side ofthe apparatus. While a mechanism serving to positively accelerate thegroups of ends towards previously deposited groups of ends forconsolidation in the outbound lanes may be provided, a retardingmechanism (schematically shown as 226 in FIG. 8) may serve the purposeof providing a continuous array of outbound articles where this isbelieved necessary.

Assuming now that it is desired to place the load regulator apparatus inoperation, it will be assumed that all trays 62 are empty and that it isdesired to begin operation. At this point, the presses furnishing thesupply of can ends are started, and as ends move down their respectivelyassociated plural conveyors and into the accumulator area where they arereceived on the individual incoming lanes. At start-up, perhaps only oneshell press might be operated initially. Inasmuch as it is assumed thatall trays are empty and that there are no ends in storage, all incomingends are transferred from inbound staging to storage. Accordingly, theappropriate signal having indicated that no transfer is to be made tothe outbound lanes, an empty tray is removed from the empty traymagazine by cycling the tray feed so as to remove a single tray 64 fromthe tray support in the empty tray magazine 50 and place it on the crossfeed conveyor 70. The tray is thereon indexed to the station 51 with itsfirst storage area or channel 65a aligned with the head.

Thereafter, as each succeeding array of ends is subdivided, placed inthe inbound staging area and picked up, it is transferred at the station51 into the next open channel 65b, 65c, etc., in the being-filled tray64. Under this assumption, the cycling just described would continueuntil a desired number of trays, say four or five, would be filled withends. Thereupon, it is assumed, the downline machine would be preparedfor operation and the apparatus 10 would receive a command to fill theoutbound staging area and the consolidation areas so as to feed can endsto the downline apparatus. In this sequence, it is assumed that thesupply of ends received from the shell press is continuing. Since thereis now a demand in the outbound staging area for a supply of ends, thepreviously subdivided sticks of ends are taken from the inbound stagingarea and transferred directly to the outbound staging area, being fedrespectively to each of the lanes in the outbound staging area as calledfor the the downstream machines.

This cycling would continue, with all transfers of article groups orsticks being achieved continually. Assuming for the moment that theinput or supply rate exactly equalled the demand rate, direct transferbetween staging areas would continue. Assuming for the moment, however,that the demand in the downstream work stations exceeds theinstantaneous supply, as would be indicated by a downstream signal sentdirectly, or by the presence of open areas in the tracks in theconsolidation areas, then in addition to the sticks of ends beingtransferred from the inbound staging area to the outbound staging area,the transfer apparatus 48 would periodically pick up sticks of ends froma channel 65a in a tray 64 in the transfer and deposit area 51. Thesesticks would be deposited in the appropriate outbound lane in theoutbound staging area, to supplement the directly supplied ends. Thistransfer from storage to the outbound staging area would occur asindicated by the demand on the downstream side. In other words, thiscycle could be repeated once every five or ten direct transfer cycles,or otherwise as often as is indicated.

Assuming that the supply of incoming ends were to cease altogether, thenthe entire oubound staging areas would be supplied with ends taken fromstorage, and the machine would cycle repeatedly in this mode only. Thus,where there is a deficit in the supply, the demand is filled by directtransfer plus supplementary ends from storage, with the possibilitybeing that anywhere between some and all of the ends could be suppliedfrom storage.

Assuming for the moment, that the supply were in excess of the demand,ends would be placed in storage as indicated; in such instance, everyfifth, tenth, twentieth stick could be placed in storage, for example.Of course, upon initial start up, or if the demand became zero as aresult of line stoppage for maintenance, access, or the like, then allinbound ends would be placed in storage on a group-by-group basis, aspreviously indicated.

Accordingly, it will be seen that any amount, including the entireinbound amount of articles could be placed in storage; any outboundamount, including all the outbound articles, could be taken fromstorage, and any proportion of the outbound articles could be suppliedfrom direct transfer to or from storage, depending upon conditions. Theconditions are instantaneously reversible, with the machine operating ona group-by-group basis. In other words, if there were temporary excessof inbound ends, they could be placed in storage and even removed fromthe same placement into storage on the same or next following cycle.Thus, the response time of the machine is substantially zero.

Referring now to FIG. 12, a schematic representation of theabove-described form of machine operation is shown. Here, operationswhich are optional or intermittently performed are shown in brokenlines, while preferred or necessary operations are shown in solidblocks.

Thus, block 300 indicates that a supply of ends is being provided froman upstream machine such as a press, and shows that these ends may beaccumulated as shown in block 302. A preferred but technically optionalstep is shown in block 304, namely, subdividing the strings of endswhich have accumulated into groups for batch handling. Block 306 showsinbound staging of ends, i.e., preparing the ends for transfer asindicated in block 308. The transfer may be a direct transfer tooutbound staging as shown at line 310, whereby the ends accumulatetransiently in the outbound staging area 312. From here the ends may beoptionally advanced to a consolidator 314 from which they are fed to adownstream machine having a given demand as represented by block 316.

According to the invention, regulation or control is accomplished in oneaspect by decreasing the instantaneous rate at which the net supply ofends is sent to the outbound staging area, and in another aspect byincreasing the instantaneous supply rate to the outbound staging area.Line 318 shows that the net supply of ends reaching the outbound stagingarea is decreased by transient storage of certain groups of ends. Here,a single container schematically designated 320 provides transientstorage or retrieval by group. An increase in the net supply rate tooutbound staging is accomplished as shown at 322, namely, by retrievinggroups of ends from the transient storage area 320 and using thesegroups to supplement the groups of ends being furnished directly frominbound to outbound staging areas from time to time. Block 323 and flowlines 324 and 326 show, respectively, storage or retrieval by container,i.e., adding ends to storage or retrieving ends from storage in fulltrays, i.e., upstacking or downstacking full trays. Step 326 showsupstacking or downstacking empty trays to add to or withdraw from thereverse tray or storage container capacity of the apparatus.

Control unit 328 is shown as detecting excess supply, block 330, therebyenabling or activating the condition shown at line 318, to decrease thenet supply of article to output; where the demand is in excess of thesupply as shown at 332, the condition in line 322 is enabled oractivated, and the supply is supplemented.

The most essential steps are, therefore, inbound and outbound staging,transfer and storage, and retrieval by group under the control of thecondition detector. Storage by container adds flexibility, while theaccumulation and subdivision of ends, as well as consolidating ends maybe considered optional in the sense that the machine need not itselfinclude these elements to incorporate the invention.

Referring now to certain individual features, the machine logic is of akind known to those skilled in the art, with various disabling andenabling controls being provided as indicated. Thus, in order for a pickup to be made from an inbound staging area, the lane must be entirelyfilled as indicated by an appropriate trailing edge sensor which wouldrequire a positive-going signal from a leading edge sensor, for example.The transfer to and taking from storage involves a complete stick, andinasmuch as the ends or other articles are loaded into the tray inindividual sticks, there is no need for gauging the stick lengths duringeach cycle.

Referring now to movement of the head portion of the transfer apparatus,the cycle time of this apparatus must be at least as many times fasterthan the fill-up time of individual infeed area as there are separateinfeed lanes. Thus, if there are four infeed lanes, each requiringtwenty seconds to be filled, the machine should be able to engage,remove, and deposit a stick in less than five seconds, so that themaximum input capacity of the apparatus could be accommodated. By thesame token, the number of transfer cycles able to be achieved by thehead is the limiting factor of supply rate to the outbound lanes. Theproximity or position sensors referred to may be of the photoelectric,magnetic, or other known type including those operating on infrared orvisible light, utilizing the "Hall" effect, or otherwise as known tothose skilled in the art.

A detailed description of the invention has been given, with regard toan embodiment wherein a single transfer head is used; it will beunderstood that two or more such transfer heads may be used whereindicated. The articles being manufactured are identified as can ends,but it will be appreciated that any kind of arrayable, mass producedarticles which are subject to transfer between work stations, includingassembly stations, are adapted for handling by the apparatus of theinvention. These include metal and plastic parts of all kinds. Theprinciples of the invention are applicable to balancing or regulatingany type of work loads.

Machines incorporating the present invention have been constructed,operated, and sold with great success; in the can industry, thesemachines are identified by the trademark "BALANCER", owned by theassignee of the present invention.

The invention is not limited to chain type conveyors, since hydraulic orother positioners may be used. A tray magazine with a vertical feed hasbeen shown, but inverting or folding type stackers may be used, andcontainers other than trays may be used. Similarly, the storage capacitymight be accommodated on, or form an integral part of, a conveyor or asingle reciprocable container. Other mechanical variations of theapparatus will suggest themselves to those skilled in the art ofindustrial process machinery. Sensing and leveling mechanisms anddetectors may be of any known kind, and the program sequence may be asindicated by the designer.

Indexing has been described as movement between adjacent channels in thetrays, but alternate or predesignated storage areas may be selectedinstead of adjacent areas only. The apparatus may also be integratedwith apparatus intended to add additional components to the line, ifdesired. In other words, more than one style of article may be handledin the machine, and articles may be prearrayed or assembled into groupsor subgroups before being handled as a subdivided group by theapparatus. The unit may be constructed so as to include the infeed andoutfeed conveyors or merely so as to be able to be interfaced with them.The method of the invention may be carried out by other types ofapparatus as well.

It will thus be seen that this invention provide a novel workloadregulator for automated production having a number of advantages andcharacteristics including those pointed herein and others which areinherent in the invention. A preferred embodiment having been describedby way of example it is anticipated that modifications may be made tothe described form of apparatus and methods without departing from thespirit of the invention or the scope of the appended claims.

We claim:
 1. An apparatus adapted to be positioned between a first workstation producing articles at a first cyclic rate and a second workstation downstream of said first station and adapted to perform anoperation on said produced articles at a second cyclic rate, saidapparatus being adapted to regulate the rate of flow between saidstations so that both stations may be operated continuously at theirdesired cyclic rates, respectively, said apparatus including meansadapted for connection to a source of inbound articles, means adaptedfor connection to a destination for said articles when said articles areoutbound from said apparatus, said apparatus also including a transferstation having at least one staging area for said inbound articles, atleast one staging area for said outbound articles, a storage placementand retrieval area, and a transfer mechanism including means for pickingup and releasing said articles in groups, means forming a part of saidtransfer mechanism for moving said pickup and releasing means betweenpositions adjacent said staging areas and a position adjacent saidstorage placement and retrieval area, means operatively associated withsaid appratus for transiently storing at least some of said groups ofarticles, and detection and control means adapted to determine the rateat which articles are being supplied to said regulating apparatus fromsaid first work station and the demand rate at which articles arerequired to be supplied to said second work station, said control meansbeing operative, when said demand rate substantially equals said supplyrate, to cause said transfer mechanism to transfer all of said groups ofarticles arriving at said inbound staging area to said outbound stagingarea at substantially the same rate at which said articles are arrivingat said inbound staging area, when said supply rate exceeds said demandrate, to cause said transfer mechanism to transfer some of said groupsof articles arriving at said inbound staging area to said outboundstaging area and the remainder of said arriving groups to said transientstorage means, and when said demand rate exceeds said supply rate, tocause said transfer mechanism to transfer all groups of articlesarriving at said inbound staging area to said outbound staging area atsubstantially the same rate at which said articles are arriving at saidinbound staging area, and to supplement the groups of articles being fedfrom said inbound to said outbound staging areas by periodicallyretrieving groups of articles from said transient storage means andtransferring them to said outbound staging area.
 2. An apparatus adaptedto be positioned between a first work station producing articles at afirst cyclic rate and a second work station downstream of said firststation and adapted to perform an operation on said produced articles ata second cyclic rate, said apparatus being adapted to regulate the rateof flow between said stations so that both stations may be operatedcontinuously at their desired cyclic rates, respectively, said apparatusincluding means defining a first area for accumulating inbound articlesbeing fed to said apparatus in a continuous array from said first workstation, a second area for accumulating outbound groups of articles foradvancement as a continuous array to said second work station, saidapparatus also including a transfer station having at least one stagingarea for said inbound articles, at least one staging area for saidoutbound articles, a storage placement and retrieval area, and atransfer mechanism including means for picking up and releasing saidarticles in groups, means forming a part of said transfer mechanism formoving said pickup and releasing means between positions adjacent saidstaging areas and a position adjacent said storage placement andretrieval area, said apparatus further including means for receiving aplurality of empty storage containers, means for receiving a pluralityof full storage containers, a storage container shuttle assemblyincluding conveying means for positioning a selected portion of one ofsaid storage containers in a predetermined position in said storageplacement and retrieval area, and detection and control means adapted todetermine the rate at which articles are being supplied to saidregulating apparatus from said first work station and the demand rate atwhich articles are required to be supplied to said second work station,said control means being operative, when said demand rate substantiallyequals said supply rate, to cause said transfer mechanism to transferall of said groups of articles arriving at said inbound staging area tosaid outbound staging area at substantially the same rate at which saidarticles are arriving at said inbound staging area, when said supplyrate exceeds said demand rate, to cause said transfer mechanism totransfer some of said groups of articles arriving at said inboundstaging area to said outbound staging area and the remainder of saidarriving groups to selected storage areas within one of said storagecontainers, and when said demand rate exceeds said supply rate, to causesaid transfer mechanism to transfer all groups of articles arriving atsaid inbound staging area to said outbound staging area at substantiallythe same rate at which said articles are arriving at said inboundstaging area, and to supplement the groups of articles being fed fromsaid inbound to said outbound staging areas by periodically retrievinggroups of articles from said storage areas in said storage containersand transferring them to said outbound staging area.
 3. An apparatus asdefined in claim 1 wherein said means adapted for connection to saidsource of said inbound articles comprises means defining at least onelane for advancing a plurality of aligned articles toward said at leastone inbound staging area, and further includes means for urging articlesoccupying said lane toward said inbound staging area.
 4. An apparatus asdefined in claim 1 wherein said means for connection to said source ofsaid inbound articles includes means defining at least one lane forreceiving an aligned array of inbound articles, wherein said apparatusincludes means for biasing said array of articles toward movement in thedirection of said inbound staging area, and wherein said apparatusfurther includes means operatively associated with said at least onelane for subdividing said continuous array of articles into separategroups, whereby said articles may be advanced to said inbound stagingarea in individual groups.
 5. An apparatus as defined in claim 1 whereinsaid at least one inbound staging area comprises a plurality of inboundstaging areas and wherein said means for connection to said source ofsaid inbound articles includes means defining a lane in which saidarticles travel for each of said staging areas.
 6. An apparatus asdefined in claim 1 wherein said means for transiently storing at leastsome of said groups of articles comprises a container which is receivedfor movement through a range of positions within said storage placementand retrieval area.
 7. An apparatus as defined in claim 1 wherein saidstaging areas are constructed and arranged so as to be spaced apart onsubstantially the same plane, and wherein said storage and retrievalarea is positioned in a plane vertically spaced apart from the planeoccupied by said staging areas.
 8. An apparatus as defined in claim 1wherein said pickup and releasing means forming a part of said transfermechanism includes a transfer head having means for mechanicallygrasping and releasing a plurality of articles arrayed in groups.
 9. Anapparatus as defined in claim 1 wherein said means forming a part ofsaid transfer mechanism includes a transfer head having means formagnetically grasping and releasing a plurality of articles arrayed ingroups.
 10. An apparatus as defined in claim 1 wherein said means forpicking up and releasing said articles in groups comprises a transferhead which is reciprocable both vertically and horizontally, and whereinsaid transfer mechanism includes a drive mechanism adapted to move saidhead to a predetermined horizontal position under the control of aposition detector, and wherein said transfer mechanism includes a drivemechanism adapted to move said head to a predetermined vertical positionunder the control of a position detector.
 11. An apparatus as defined inclaim 1 wherein said means adapted for connection to said destinationfor said outbound articles includes means defining a lane for each lanewhich forms a part of said outbound staging area.
 12. An apparatus asdefined in claim 1 wherein said means adapted for connection to saiddestination comprises means for urging individual groups of articlesalong a feed path having an outlet connected to an article outfeedconveyor, said feeding means serving to advance and consolidate saidgroups of articles into a single continuous array of articles.
 13. Anapparatus as defined in claim 1 wherein said means for transientlystoring at least some of said groups of articles comprises a movablecontainer, and means for moving said container in one direction whilegroups of articles are being added to said container for storage and inanother direction when groups of articles are being retrieved fromstorage in said container.
 14. An apparatus as defined in claim 1wherein said transfer of articles from said inbound staging area to saidoutbound staging area at said substantially same rate comprisestransferring articles in groups directly from said at least one inboundlane to said at least one outbound lane.
 15. An apparatus as defined inclaim 1 wherein said at least one inbound and outbound staging areaseach comprise plural staging areas and wherein the number of inboundstaging areas is equal to the number of outbound staging areas.
 16. Anapparatus as defined in claim 1 wherein said at least one inbound andoutbound staging areas each comprise plural staging areas and whereinthe number of inbound staging areas is is not equal to the number ofoutbound staging areas.
 17. An apparatus as claimed in claim 2 whereinsaid area for accumulating inbound articles further includes means forsubdividing said continuous array of inbound articles into individualgroups of articles.
 18. An apparatus as defined in claim 2 wherein saidmeans for receiving said plurality of empty and full storage containerscomprises respectively an empty container magazine and a full containermagazine, with each magazine including means for supplying individualcontainers to said conveying means without movement of the remainingcontainers in said magazine.
 19. An apparatus as defined in claim 2wherein said means for receiving said empty and full storage containersrespectively comprise container magazines along opposite sides of saidtransfer station and wherein said shuttle assembly conveying meansincludes a conveyor having an upper run extending between said magazinesand extending through said transfer station.
 20. An apparatus as definedin claim 2 wherein said means for receiving said empty and full storagecontainers respectively comprise container magazines along oppositesides of said transfer station and wherein said shuttle assemblyconveying means includes a conveyor having an upper run extendingbetween said magazines and extending through said transfer stationbeneath the level at which said inbound and outbound staging areas arelocated.
 21. An apparatus as defined in claim 2 wherein each of saidcontainers includes means defining a plurality of channels, each ofwhich is adapted to receive a group of articles.
 22. An apparatus forregulating the flow rate of an apparatus for articles moving between anupstream work station serving as a source of supply for such articles,and a downstream station having a demand for such articles, saidapparatus having means for transiently accumulating inbound articlesbeing fed in a continuous array, means for subdividing said continuousarray of articles into individual groups, means for accumulating groupsof articles intended to be fed downstream and means for advancing andconsolidating said groups into at least one continuous array of articlesdestined for said downstream work station, article group transfer meansadapted to engage and transport said individual inbound groups ofarticles to said area in which said articles are to be accumulated foradvancement downstream, means for transferring selected groups ofarticles from said inbound accumulating area to a storage area in astorage container means and for removing groups of articles from astorage area in said storage container means and transferring them tosaid area in which said downstream bound articles are accumulating, atleast one storage container means and means for positioning said storagecontainer means so as to provide registration between a desired area ofsaid storage container means and a portion of said article grouptransfer means when said group of articles is being placed in saidstorage container means, and for registering a group of articles in saidstorage container means with said article group transfer means when saidgroup of articles is to be transferred from said container means to saidarea in which said downstream bound articles are accumulating, andcontrol means adapted to move said article group transfer means so as tosupplement the number of groups of articles being fed to said downstreamwork station from said upstream work station by adding groups ofarticles taken from said storage container means to said groups beingtransferred from said area in which said inbound articles areaccumulating, and for diminishing the supply of articles fed to saidarea in which said downstream bound articles are accumulating bytransferring groups of articles from said area at which said inboundarticles are accumulating to said storage area within said storagecontainer means.